Kodiak bears track salmon runs in Alaska

June 1, 2016, University of Montana
An Alaskan brown bear enjoys a salmon meal. Credit: Photo by Jonny Armstrong

A University of Montana graduate student's research on Alaskan brown bears and red salmon is the May cover story of the high-profile journal Ecology.

Will Deacy, a UM systems ecology graduate student under the direction of UM Professor Jack Stanford, researched on Kodiak Island, Alaska, in collaboration with the U.S. Fish and Wildlife Service.

Brown bears are faced with a challenge: They need to consume lots of salmon each year, but salmon only are available for a few weeks in each shallow ground. However, salmon spawn at different times in different habitats, which could allow bears to eat salmon for long periods of time if they move to different spawning grounds. GPS collars allowed Deacy to observe where and when bears foraged for salmon.

"We found that the bears greatly extend their use of the salmon resource by migrating from one run to another," Stanford said. "We call this 'surfing the salmon red wave.'"

"This research shows wildlife have very sophisticated foraging behaviors," Deacy said. "The bears benefited from variation in spawning timing, which is ultimately created by complex natural watersheds. This highlights the need to conserve complexity in wild places."

Deacy conducted his field work over the course of five years in the soggy and remote Karluk area of southwestern Kodiak Island, which is accessible only by float plane. The area has one of the most dense brown bear populations on Earth. It also has hundreds of rivers, streams and lake beaches used by spawning Pacific salmon.

The researchers' studies of Alaskan are ongoing. They want to understand how human activities, like bear viewing and low-level flying, impact brown bear foraging behavior.

Explore further: The bear necessities of aging

More information: William Deacy et al, Kodiak brown bears surf the salmon red wave: direct evidence from GPS collared individuals, Ecology (2016). DOI: 10.1890/15-1060.1

Related Stories

The bear necessities of aging

December 12, 2007

According to George Bernard Shaw: “We don’t stop playing because we grow old; we grow old because we stop playing,” but how fast does that aging occur once started" In the case of populations of salmon in Alaska studied ...

Why letting salmon escape could benefit bears and fishers

April 10, 2012

New research suggests that allowing more Pacific salmon to spawn in coastal streams will not only benefit the natural environment, including grizzly bears, but could also lead to more salmon in the ocean and thus larger salmon ...

A single hair shows researchers what a bear has been eating

July 28, 2015

U.S. and Canadian researchers have found they can get a good idea of a grizzly bear's diet over several months by looking at a single hair. The technique, which measures residues of trace metals, can be a major tool in determining ...

Salmon sickness detected in farmed Canadian fish

May 20, 2016

Researchers led by a Canadian government scientist have diagnosed potential heart and skeletal muscle inflammation in farmed salmon from British Columbia province, the Canadian fisheries ministry announced Friday.

Recommended for you

In colliding galaxies, a pipsqueak shines bright

February 20, 2019

In the nearby Whirlpool galaxy and its companion galaxy, M51b, two supermassive black holes heat up and devour surrounding material. These two monsters should be the most luminous X-ray sources in sight, but a new study using ...

When does one of the central ideas in economics work?

February 20, 2019

The concept of equilibrium is one of the most central ideas in economics. It is one of the core assumptions in the vast majority of economic models, including models used by policymakers on issues ranging from monetary policy ...

Research reveals why the zebra got its stripes

February 20, 2019

Why do zebras have stripes? A study published in PLOS ONE today takes us another step closer to answering this puzzling question and to understanding how stripes actually work.

Correlated nucleons may solve 35-year-old mystery

February 20, 2019

A careful re-analysis of data taken at the Department of Energy's Thomas Jefferson National Accelerator Facility has revealed a possible link between correlated protons and neutrons in the nucleus and a 35-year-old mystery. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.